Project Summary Children living in rural areas are 25% more likely to be overweight than their metropolitan peers. Little research has focused on strategies to address this disparity. Developing and evaluating cost-effective interventions that positively impact children's long-term weight status and related health parameters are critical to promoting improved health of youth in rural settings. Successful treatment of childhood obesity can yield significant health benefits. Behavioral family-based interventions, including both the child and parent, have demonstrated success in producing weight loss in children. The generalizability of these interventions, however, is limited. Few trials have been conducted in medically underserved community settings. The level of resources needed to deliver effective interventions represents a significant barrier to dissemination into rural community settings. A growing body of researchsuggests that exclusively targeting parents in the treatment of childhood obesity may be as effective as family-based programs. A parent-only intervention may be a particularly beneficial and cost-effective alternative for rural populations. Data from our pilot lifestyle intervention (R34 DK071555) delivered through Cooperative Extension Service (CES) offices in rural communities suggests that a parent- only intervention may be a cost-effective alternative intervention to family-based programs in these rural settings. The next logical step in this line of research is to evaluate the long-term effects of comprehensive Family-Based and Parent-Only behavioral interventions on measures of child weight and health status, and cost-effectiveness. The proposed study entails a three arm RCT to test the effectiveness of interventions designed to promote long-term weight management and improved health status in overweight and obese children from medically underserved, rural areas. Children (n = 240), ages 8-12 years, and their parent(s) will be randomly assigned to a Parent-Only (PO), Family-Based (FB), or a Health Education Control (HEC) intervention. Both the PO and FB interventions will take a behavioral lifestyle approach to modify dietary and physical activity patterns. In the PO intervention, only the parent(s) will attend group meetings, while in the FB intervention both the child and parent(s) will attend group sessions. Both the child and parent(s) will attend group sessions in the HEC condition. All interventions will be delivered through CES offices and will include 12 sessions over the course of 4 months, followed by monthly group sessions for the next 8 months. Weight status, metabolic parameters, physical activity, nutritional intake and quality of life will be assessed at baseline, post-treatment (month 12), and follow-up (month 24). We will also evaluate the cost effectiveness of these interventions. It is hypothesized that: (a) children in the PO and FB will exhibit greater improvements in weight status than children in the HEC at months 12 and 24, and (b) the PO will demonstrate greater cost- effectiveness than the FB and HEC. Results may have significant implications for treatment of pediatric obesity in underserved rural areas by identifying a cost-efficient and effective alternative to family-based interventions.